Process for dyeing nylon in pink shades

ABSTRACT

THE PROCESS FOR DYEING NYLON FIBERS WHICH COMPRISES CONTRACTING SAID FIBERS WITH A DYE OF THE STRUCTURE   2-(H2N-),2-((4-R,(M-O3S-)PHENYL)-O-),4-(HO-)ANTHRAQUINONE   WHEREIN M IS -H OR -NA AND R IS -H OR AN ALKYL GROUP OF 1-9 CARBONS AND THE NYLON FIBERS DYED WITH SAID DYE.

United States Patent 3,627,473 PROCESS FOR DYEING NYLON IN PINK SHADES Robert W. Eltonhead, Reading, Pa., assignor to Crompton & Knowles Corporation, Worcester, Mass. No Drawing. Filed May 3, 1965, Ser. No. 452,848

Int. Cl. D061) N20 US. Cl. 8-21 B 7 Claims ABSTRACT OF THE DISCLOSURE The process for dyeing nylon fibers which comprises contacting said fibers with a dye of the structure 0 0H s'o M wherein M is H or -Na and R is -H or an alkyl group of 19 carbons and the nylon fibers dyed with said dye.

- SO3H n R O OH (Structure A) wherein R represents a substituent selected from the group consisting of H and alkyl groups having from 1 to 9 carbons; raising the temperature of the bath to about 200 F., maintaining the fiber in contact with the dye liquor for a sufiicient time to exhaust dye onto the fiber, lowering the pH of the bath to render it mildly acid maintaining the fiber and acidified dye liquor in contact for a sufiicient time to substantially completely exhaust the dye from the bath onto the fiber, and then removing the fibers from the bath.

As described in my co-pending application entitled Pink Dye for Nylon being filed simultaneously herewith, the Structure A dyes for use in the process of this invention are obtained by sulfonating known l-amino-2- phenoxy-4-hydroxy anthraquinones having an unsubstituted phenoxy ring or C to C alkyl substituents in the phenoxy ring that provide the desired R substitution under conditions that will introduce a single sulfonic group in the dye molecule.

The unsulfonated anthraquinone precursors of the Structure A dyes have been reported as being useful as dispersed dyes for synthetic fibers. When applied as dispersed dyes they impart red shades toacetate, triacetate, modacrylic, polyester and nylon fibers and they merely stain without dyeing cotton, acrylic, silk and wool fibers.

The Structure A dyes have different, unique and unexpected properties as compared to their unsulfonated precursors. They are acid dyes for natural and synthetic polyamide fibers such as silk, wool and nylon. They do not dye and exhibit good reserving properties with re- 3,627,473 Patented Dec. 14, 1971 ice spect to acetate, triacetate, acrylic, modacrylic and polyester fibers.

The Structure A dyes impart to the polyamide fibers bright, bluish red shades having a high degree of lightfastness. Further, and in contrast to their unsulfonated anthraquinone precursors, the Structure A dyes will produce superior washfastness for a given depth of shade and their sublimation fastness is also superior. After treatments with conventional fixatives or fastening agents such as tannic acid-tartar emetic, so-called back tanning agents or syntans, etc. greatly enhance the washfastness of dyeings produced using the Structure A dyes, whereas such after treatments have little or no effect on the washfastness of dyeings made with the unsulfonated precursor applied as a dispersed dye.

In carrying out the process of this invention, it is preferred to use Structure A dyes in which the R substituent is an alkyl radical having from 5 to 9 carbons, because they will dye nylon from neutral solution with a very high degree of exhaustion and thereby minimize the danger of fiber degradation that can occur when dyes must be applied from hot strongly acid dye baths. However, if the R group contains less than 5 carbons, the neutral dyeing capabilities will be lowered. Further, if the R group contains more than 9 carbons, and as the number of carbons in the R group increases over 9, the neutral dyeing capabilities will become increasingly impaired.

The sulfonation of the anthraquinone precursor is carried out in a conventional manner under a variety of acid strength, times and temperatures so as to introduce a sulfonic group into the dye molecule. The exact positioning of the sulfonic group on the phenoxy ring is not known and it could be in either of the ortho or meta posi tions or it could even consist of a mixture of the ortho and meta substituted s-ulfonics. In any event, the anthraquinone precursor and the oleum are reacted in quantities that only an average of one sulfonic group is introduced in the dye. The completion of sulfonation may be determined by testing the solubility of a drop of the sulfonation reaction mass in hot water. When sulfonation is complete, no insoluble starting material will be observed.

In carrying out the process of this invention, the fibers are maintained in contact with the neutral dye liquor for a sufiicient time to exhaust dye onto the fiber. With most of the Structure A dyes a substantial portion of the dye will exhaust onto the fiber from the neutral (pH 6.5 to 7.5) dye bath within about thirty minutes at temperatures of about 200 F. To fully exhaust the dye onto the fiber, it is necessary to lower the pH of the bath to render it mildly acid. Thus, in the case of Structure A dyes where R is a C to C alkyl group substantially complete exhaustion can be obtained if the pH of the bath is lowered to about 6, and for other Structure A dyes substantially complete exhaustion is obtained when the pH is lowered to about 3.5; in both cases the fiber being maintained at elevated temperatures of about 200 F. for an additional time of about 30 minutes.

The following examples will serve to illustrate the production of the Structure A dyes, illustrate their unique dyeing capabilities, and the method of dyeing textiles with such dyes.

EXAMPLE 1 144 grams of octyl phenol, 11.8 grams of potassium carbonate, calcined and 20.4 grams of 1 amino 2 bromo 4 hydroxy anthraquinone were heated with stirring to C. and held at 150 C. for 5 hours. After cooling, methanol was added and the slurry (500 ml. vol.) was filtered. The filter cake was washed with methanol, then water, then dried. Obtained 18.8 grams of 1 amino 2 octylphenoxy 4 hydroxy anthraquinone. 10 grams of this was sulfonated by adding it over 30 minutes with stirring to 79 ml. of 25% oleum while holding the temperature under 20 C. by means of a cooling bath. After stirring for four hours at room temperature, the sulfonation mass was drowned in ice and water, then filtered. The filter cake was slurried in water, neutralized with caustic soda, filtered and dried. Obtained a dye of Structure A in which R is l I CH H CH EXAMPLE 2 140 grams of para tert. amylphenol, 11.8 grams of potassium carbonate, calcined and 25.4 grams of 1 amino 2 bromo 4 hydroxy anthraquinone were heated with stirring to 150 C. and held at that temperature for 5 hours. After cooling methanol was added and the slurry was filtered, the filter cake being washed with methanol then water. After drying 25.8 grams of 1 amino 2 amylphenoxy 4-hydroxy anthraquinone were obtained. grams of this was sulfonated with 150 grams of 25 oleum for 3 hours at 12 to 20 C. After drowning in ice and water (volume 500 ml. at 12 C.) it was filtered. The filter cake was added to water and made alkaline to a pH of 9.5 with caustic soda, heated to a boil and filtered. 100 grams of salt was added to the filtrate and the precipitated product was filtered off and dried. Obtained a dye of Structure A in which R is EXAMPLE 3 1 amino 2 bromo 4 hydroxy anthraquinone 36.4 grams, 85% phenol 140 grams and potassium carbonate 20.5 grams were heated to and held at 120 C. the water distilling off. After 18 hours at 120 C. the reaction was cooled and diluted with water (vol. at 800 ml.). It was then filtered and the filter cake washed with water till the filtrate was colorless. The filter cake of 1 amino 2 phenoxy 4 hydroxy anthraquinone when dry weighed 32.8 grams. 10 grams of this was sulfonated by adding it with stirring to 150 grams of 25 oleum while the temperature was held at 2124 C. by means of a cooling bath. After stirring for an hour at 2428 C. it was dro vned in ice and water. The 400 ml. volume at 28 C. was filtered. The filter cake was dissolved in water and caustic soda added to a pH of 11.0. It was heated to 60 C. and filtered. 100 grams of salt was added to the 1,000 ml. of filtrate, the pH adjusted to 7.4 with hydrchloric acid and the precipitate filtered off and dried. Obtained a compound of Structure A in which R is H.

EXAMPLE 4 130 grams of para tert. butyl phenol, 11.8 grams of anhydrous potassium carbonate and 25 grams of 1 amino 2 bromo 4 hydroxy anthraquinone were heated with stirring to 150 C. and held at that temperature for 6 hours. After cooling, 300 ml. of methanol were added and the slurry was filtered. After washing with methanol followed by water the filter cake was dried. Obtained 23.5 grams of 1 amino 2 para tert. butylphenoxy 4 hydroxy anthraquinone. 10 grams of this was sulfonated by adding it to 150 grams of 25 oleum over 10 minutes while holding the temperature at 17-19 C., by means of a cooling bath. After stirring the sulfonation for 3 hours at room temperature it was drowned in ice and water and the resulting 400 ml. volume was filtered. The filter cake was slurried in water containing 10% salt, neutralized with caustic soda, filtered and dried. Obtained a compound of Structure A in which R is grams of nonyl phenol, 11.8 grams of potassium carbonate, calcined and 25.4 grams of 1 amino 2 bromo 4 hydroxy anthraquinone were heated at C. for 5 hours. After cooling, ml. of methanol were added followed by 40 ml. of water. The slurry was filtered and the filter cake washed with 80% methanol, then water. Yield on drying 26.8 grams of 1 amino 2 nonylphenoxy 4 hydroxy anthraquinone. The sulfonation of 10 grams was then carried out in the same manner as described in Example 2 to provide a dye of Structure A in which R is branched chain C alkyl group.

EXAMPLE 6- .5 gram of dyestuff from Example 2 (sulfonated 1 amino 2-p-amylphenoxy 4 hydroxy anthraquinone sodium salt) was dissolved in boiling soft water following which the volume for the dye solution was adjusted to 500 ml. with additional soft water. 5 ml. of this solution was then placed in each of four 400 ml. dye beakers and the solution in each beaker was made up to 250 ml. with soft water. The dye bath solutions had a pH of 8.4 at 22 C. At room temperature, a 5 gram piece of multifiber made up of strips of acetate, acrylic (Acrilan) triacetate (Arnel) cotton, acrylic (Creslan 61), polyester (Dacron 54), polyester (Dacron 66) acrylic (Orlon 42) silk, modacrylic (Verel A), viscose and wool, was introduced into one of the dye bath solutions and a 5 gram piece of nylon 66 tricot dull was introduced into each of the other three dye bath solutions. The temperature of the dye bath solutions was then raised to 200-210 F. Throughout the course of the dyeing a stirring rod in each of the dye beakers was used to keep the fabric in motion. After /2 hour at 2002l0 F., 5 ml. of 10% monosodium phosphate solution was added to one of the dye beakers containing the nylon tricot, resulting in a dyebath pH of about 6. Five ml. of 10% acetic acid solution was added to another of the dye beakers containing the nylon tricot, resulting in a dyebath pH of about 3.5. After a further V2 hour at 200210 F. the multifiber and the three nlyon pieces were removed, rinsed in water and dried.

The nylon, silk and wool bands on the multifiber were dyed red, whereas the polyester was only slightly stained. The nylon tricot pieces were all dyed about the same depth of shade. The baths to which monosodium phosphate and acetic acid dye had been added showed complete exhaustion of color. In the neutral dyebath only a trace of color remained. When the dyeings were made in the above manner using the dyestuif (sulfonated l-amino- 2-octylphenoxy-4-hydroxy anthraquinone) obtanied from Example 1 the color of the dye liquor remaining in the neutral dyebath after the dyeing was even less than that obtained with the dyestuff from Example 2 (sulfonated 1-amino-2-amylphenoxy-4-hydroxy anthraquinone). On the other hand, when dyeings were made in the above manner using dyestuffs which had been prepared from phenol (Example 3) or alkylphenols where the alkyl group was less than 5 carbons (Example 4), the dye liquor remaining after the neutral dyeing had been carried out was strongly colored and contained an almost equal or even greater amount of dyestuif than that which was on the neutral dyeing of the nylon tricot itself. This was de termined by adding 5 ml. of 10% acetic acid solution to the remaining neutral dye liquor from which the original nylon dyeing had been removed, introducing a fresh piece of nylon tricot and continuing the dyeing until the dyebath was exhausted. After rinsing and drying the depth of shade of the dyeing was then compared with the depth of shade of the neutral dyeing.

EXAMPLE 7 .2 gram of dyestuff from Example 2 was added to 1200 ml. of soft water which was heated to a boil to effect solution. The dye solution was cooled to 160 F. and four 5 gram pieces of nylon 66 tricot dull were introduced. While the fabric was stirred in the dyebath, the temperature of the dyebath was raised to ZOO-210 F. and held for one hour, following which the fabric pieces were rinsed and dried. The nylon was dyed a bright bluish red.

EXAMPLE 8 .2 gram of unsulfonated dyestuff (l-amino-Z-para tert. amylphenoxy-4-hydroxy anthraquinone) used in preparing the dye in Example 2 is dissolved in 20 ml. of acetone. The solution was added to a solution of 2 grams of Lignin sulfonate dissolved in 1200 ml. of soft water contained in a dye beaker and the acetone removed by boiling. Four 5 grams pieces of nylon tricot were introduced. While the fabric was stirred in the dyebath, the temperature was held at ZOO-210 F. for one hour following which the fabric pieces were rinsed and dried. The nylon was dyed a dull bluish red.

EXAMPLE 9 Two of each of the following solutions were prepared.

Solution A.2 gram of Cenekol (Althouse) in 300 ml.

of solf water.

Solution B.3 gram of Erional N.W. (Geigy) in 300 ml.

of solf water.

Solution C.1 gram tannic acid, .1 gram acetic acid, .1

gram of tratar emetic in 300 ml. of soft water.

A piece of dyed fabric from Example 7 was introduced into one set of each solution and a piece of dyed fabric from Example 8 'was introduced into the other set of solutions.

The two sets of A, B, C solutions each containing a 5 gram piece of dyed nylon fabric were heated to 180 F. and held there for about 20 minutes, following which they were rinsed and dried. A number III wash test (AATCC Standard Test Method 36-1961) was run on the two sets of fabric from A, B, C, along with the untreated pieces. All aftertreated fabrics prepared from the fabric of Example 7 samples showed an improvement in washfastness over the dyed fabric from Example 7 and the samples of fabric from Example 7 that were aftertreated as set forth in this example were superior to that of dyeings made according to Example 8 even when such fabrics were aftertreated as in this example. The washfastness of fabric of Example 8 was poor, and aftertreatment according to this example produced no improvement.

In the dyeing of fabrics composed of mixed fibers such as polyester polyamide blends, the use of the Structure A dyes where R is a C to C alkyl group makes possible a better control of the dyeing by the dyer because of the enhanced substantivity of the dye for the polyamide and high degree of reservation of the polyester.

In addition to the free acid, it will be understood that the Structure A compounds of use in the process of this invention also include the soluble salts thereof.

I claim:

1. The method of dyeing natural and synthetic polyamide fibers which comprises entering the fibers into a substantially neutral aqueous dye bath at about room temperature, said bath containing a dye having the structure-- wherein R represents a substituent selected from the group consisting of H and alkyl groups having from 1 to 9 carbons; raising the temperature of the bath to about 200 F., maintaining the fiber in contact with the dye liquor for a sufficient time to exhaust dye onto the fiber, lowering the pH of the bath to render it mildly acid maintaining the fiber and acidified dye liquor in contact for a sufficient time to substantially completely exhaust the dye from the bath onto the fiber, and then removing the fibers from the bath.

2. The method according to claim 1 wherein R is an alkyl group having from five to nine carbons.

3. The dyeing produced by the method of claim 1.

4.. The method according to claim 1 wherein the dyed fibers are aftertreated with a fastening agent.

5. The method according to claim 2 wherein the polyamide fibers are blended with polyester fibers.

6. The process of dyeing nylon fibers which comprises contacting the fibers with a substantially neutral aqueous dye bath containing a dye of the structure References Cited UNITED STATES PATENTS 2,845,443 7/1958 Hindermann et al. 839 X 3,035,058 5/1962 Gunthard 839 X 3,174,983 3/1965 Ramanathan 839 X OTHER REFERENCES I. Gunthard: American Dyestuif Reporter, Jan. 14, 1957, pp. 9-16, 8-39 lit.

LORRAINE A. WEINBERGER, Primary Examiner E. J. SKELLY, Assistant Examiner U.S. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Dated December 14 1971 Patent No. 3 627 473 Inventor(s) Robert W. Eltonhead It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In column 5, change line 45 to read:

-over the dyed fabric from Example 7. The

washfastness of the fabric from Example 7 and the samples-- Signed and sealed this 5th day of September 1972.

Attesting Officer USCOMM-DC 60376-P69 s u.5. GOVERNMENT PRINTING OFFICE: I969 o-aes-au FORM F-O-105O (10-69) 

